| Epoch-level exclusions | Freq | Cumulative Freq | Percent | Cumulative Percent |
|---|---|---|---|---|
| 1. Not in the sleep period | 1364837 | 1364837 | 80.19 | 80.19 |
| 2. Missing veteran activity | 547 | 1365384 | 0.03 | 80.22 |
| 3. Missing dog activity | 35436 | 1400820 | 2.08 | 82.30 |
| 4. Missing Purdue sleep/wake classification | 15 | 1400835 | 0.00 | 82.30 |
| NA | 301245 | 1702080 | 17.70 | 100.00 |
| Night-level exclusions | Freq | Cumulative Freq | Percent | Cumulative Percent |
|---|---|---|---|---|
| 1. No veteran activity during the sleep period | 1 | 1 | 0.15 | 0.15 |
| 2. No dog movement during the sleep period | 25 | 26 | 3.70 | 3.85 |
| NA | 650 | 676 | 96.15 | 100.00 |
Characteristic | N = 56 |
|---|---|
Bluetooth proximity, mean nightly minutes | |
Range | 175, 543 |
Median (IQR) | 396 (342, 443) |
Mean (SD) | 386 (81) |
Service dog in the room, mean nightly minutes | |
Range | 0, 579 |
Median (IQR) | 393 (319, 465) |
Mean (SD) | 372 (135) |
Missing | 5 |
Service dog in the bed, mean nightly minutes | |
Range | 0, 535 |
Median (IQR) | 327 (86, 438) |
Mean (SD) | 274 (189) |
Missing | 5 |
Characteristic | N = 56 |
|---|---|
Bluetooth proximity, mean nightly percent | |
Range | 38.4, 99.8 |
Median (IQR) | 90.7 (80.6, 98.2) |
Mean (SD) | 86.8 (14.1) |
Service dog in the room, mean nightly percent | |
Range | 0.0, 100.0 |
Median (IQR) | 95.5 (75.4, 100.0) |
Mean (SD) | 82.4 (27.2) |
Missing | 5 |
Service dog in the bed, mean nightly percent | |
Range | 0.0, 100.0 |
Median (IQR) | 81.8 (20.1, 100.0) |
Mean (SD) | 60.9 (40.3) |
Missing | 5 |
We want to characterize the extent to which the veteran and service
dog were active at the same times during the night (without
dichotomizing the activity data).
We can approach this by ranking the epoch-level activity data for the veteran, ranking the epoch-level activity data for the service dog, and then compare the ordering of the rankings each night to get a nightly measure of the extent to which the veteran and service dog were active during the same epochs.
Kendall’s tau is a measure of rank correlation. There are different versions of Kendall’s tau that handle ties in different ways. For most of the epochs the ranks are the same (i.e. due to zeros) for both the veteran and the dog, representing ties that need to be handled.
Pimentel, et al proposed an estimator based on Kendall’s tau for zero-inflated continuous variables. Perrone et al provided R code in Supplementary materials to calculate the estimator proposed by Pimentel et al, as well as their proposed estimator of Kendall’s tau for bivariate zero-inflated count data.
Characteristic | N = 56 |
|---|---|
Mean nightly percent agreement | |
Range | 0.63, 0.88 |
Median (IQR) | 0.80 (0.76, 0.83) |
Mean (SD) | 0.79 (0.05) |
Mean nightly Cohen's kappa | |
Range | 0.31, 0.85 |
Median (IQR) | 0.73 (0.66, 0.78) |
Mean (SD) | 0.71 (0.10) |
Mean nightly Kendall's Tau | |
Range | -0.02, 0.15 |
Median (IQR) | 0.04 (0.03, 0.06) |
Mean (SD) | 0.04 (0.03) |
Characteristic | N = 56 |
|---|---|
Concordant - both sleeping, mean nightly minutes | |
Range | 190, 449 |
Median (IQR) | 330 (302, 368) |
Mean (SD) | 334 (60) |
Concordant - both awake, mean nightly minutes | |
Range | 5, 83 |
Median (IQR) | 16 (12, 22) |
Mean (SD) | 18 (11) |
Discordant - veteran sleep, dog awake, mean nightly minutes | |
Range | 19, 89 |
Median (IQR) | 46 (38, 56) |
Mean (SD) | 48 (16) |
Discordant - veteran awake, dog sleeping, mean nightly minutes | |
Range | 6, 115 |
Median (IQR) | 43 (31, 60) |
Mean (SD) | 46 (22) |
Characteristic | N = 56 |
|---|---|
Concordant - both sleeping, mean nightly percent | |
Range | 45.4, 84.8 |
Median (IQR) | 76.2 (70.9, 79.8) |
Mean (SD) | 74.8 (7.2) |
Concordant - both awake, mean nightly percent | |
Range | 1.2, 17.4 |
Median (IQR) | 3.5 (2.6, 4.6) |
Mean (SD) | 3.9 (2.4) |
Discordant - veteran sleep, dog awake, mean nightly percent | |
Range | 4.2, 24.9 |
Median (IQR) | 10.4 (9.0, 12.1) |
Mean (SD) | 10.8 (3.8) |
Discordant - veteran awake, dog sleeping, mean nightly percent | |
Range | 1.9, 26.4 |
Median (IQR) | 9.8 (6.5, 12.7) |
Mean (SD) | 10.5 (5.2) |
Walters et al calculated four transmission variables.
1. Percent transmissions received: the percentage of an
individual’s awakenings in a given time interval classified as a wake
transmission (i.e., total number of transmitted wakes received by
individual/total awakenings in individual).
2. Percent minutes resistant to transmission:
percentage of a bedpartner’s nocturnal wake minutes during which an
individual slept.
3. Number of transmissions received: the total number
of transmission events in a given time interval.
4. Transmissibility: the percentage of the bedpartner’s
awakenings in a given time interval that were classified as wake
transmissions (i.e., number of wake transmissions received/total
bedpartner awakenings: a measure of vulnerability to a bedpartner’s
awakenings.
Characteristic | N = 56 |
|---|---|
Percent transmissions received - veteran | |
Range | 6.6, 32.7 |
Median (IQR) | 13.8 (11.3, 18.6) |
Mean (SD) | 15.1 (5.7) |
Percent transmissions received - service dog | |
Range | 3.9, 49.0 |
Median (IQR) | 22.2 (15.2, 25.8) |
Mean (SD) | 21.5 (9.2) |
Percent minutes resistant to transmission - veteran | |
Range | 40.3, 91.2 |
Median (IQR) | 74.3 (68.6, 80.0) |
Mean (SD) | 73.3 (10.2) |
Percent minutes resistant to transmission - service dog | |
Range | 43.2, 87.4 |
Median (IQR) | 72.1 (65.9, 77.5) |
Mean (SD) | 71.2 (9.2) |
Number of transmissions received - veteran | |
Range | 1.2, 6.8 |
Median (IQR) | 3.3 (2.5, 4.4) |
Mean (SD) | 3.5 (1.4) |
Number of transmissions received - service dog | |
Range | 1.1, 15.1 |
Median (IQR) | 6.0 (4.4, 8.5) |
Mean (SD) | 6.7 (3.2) |
Transmissibility - veteran | |
Range | 4.2, 20.9 |
Median (IQR) | 10.1 (8.8, 13.5) |
Mean (SD) | 11.1 (3.5) |
Transmissibility - service dog | |
Range | 8.6, 82.1 |
Median (IQR) | 25.5 (20.0, 32.5) |
Mean (SD) | 27.9 (13.0) |